Dehumidifier having unitary evaporator-condenser plate



C. H. WURTZ Jan. 29, 1957 DEHUMIDIFIER HAVING UNITARY EVAPORATOR-CONDENSER PLATE Filed April 25, 1955 N TOR. C/iffarcl Q Zr/Z Hi6 ATTOITIE y United States Patent DEHUMIDIFIER HAVING UNITARY EVAPORA- TOR-CONDENSER PLATE Clifford H. Wurtz, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application April 25, 1955, Serial No. 503,481

7 Claims. (Cl. 62-140) Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings: Figure 1 is a perspective view with parts broken away showing a preferred embodiment of the invention;

Figure 2 is an end elevational view showing the air contacting heat exchangers;

Figure 3 is a fragmentary developed view showing the construction and arrangement of the evaporator, condenser and restrictor assembly; and

Figure 4 is a sectional view taken on line 4-4 of Figure 3.

Referring now to Figure l of the drawing wherein a preferred embodiment of the invention has been shown, reference number 10 generally designates the main casing of a dehumidifier having an air inlet 12 adjacent its one end and an air outlet 14 adjacent its other end. A fan 16 is arranged as shown for circulating air through the housing in accordance with well known practice, A refrigerating system is used for removing moisture from the air circulated through the housing and this system consists of a conventional sealed motor-compressor unit 20 which serves to discharge compressed refrigerant through a line 22 which leads to the inlet of a one-piece roll forged combination condenser and evaporator plate generally designated by the reference numeral 24.

The plate 24 is made by the roll forging process disclosed in Long Patent No. 2,662,273. Since this process is fully disclosed in the Long patent and is now well known to those skilled in the art it will not be described in greater detail. The plate 24 is provided with internal condenser passages 26 which are arranged along substantially the full length of the roll bonded plate 24 adjacent the one edge of the plate. The compressed refrigerant entering the passages 26 is condensed therein and leaves the plate 24 and then flows into a conventional capillary tube type of fixed restrictor 27 before being returned to the evaporator passage means 28 located adjacent the other edge of the plate 24. The liquid refrigerant supplied to the evaporator passage 28 is evaporated therein and then returns to the compressor in vapor form through the usual suction line 30.

The air to be dehumidified enters the casing 10 through the inlet 12 and flows through an air filter 32 and then Patented Jan. 29, 1957 comes into contact with the evaporator portion 28 of the roll bonded plate 24 so as to have moisture removed therefrom in accordance with well known principles. The air leaving the evaporator 24 immediately passes over the condenser portion of the roll bonded plate 24 after which it flows in thermal exchange relationship with the motor-compressor unit and is then returned to the room through the air outlet grill 14.

The roll bonded plate 24 is provided with a plurality of longitudinally extending slots 40 which prevent the direct transfer of heat between the condenser portion and the evaporator portion. The narrow portions of metal 42 between the slots 40 serve to hold the evaporator and condenser in proper relationship with respect to one another but are narrow enough to restrict excessive transfer of heat by conduction. After the roll bonded plate 24 is provided with the refrigerant passages and slots 40 described hereinabove it is formed into a spiral shape as shown in Figure 2 whereby a plurality of the convolutions of the spiral are exposed to the air circulating through the housing 10.

The advantage of using a roll bonded heat exchanger arrangement of the type described herein is that both the evaporator and condenser may be manufactured cheaply and handled as one piece. Another advantage of the construction shown is that it is possible to expose a large amount of live heat transfer surface to the air flowing in thermal exchange relationship with the refrigerant and to obtain good drainage of the condensate into the usual condensate collecting drawer 50 located in the bottom of the casing 10. Still another advantage is that the irregular exterior surface which results from the depressions 44 in the outer surface of the roll bonded plate creates the desired turbulence for etlicient transfer of heat between the air and the surfaces of the heat exchanger.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

1. In a unitary portable dehumidifying apparatus having a common supporting means, a refrigerant evaporating means, a refrigerant condensing means, a refrigerant compressing means connected in series refrigerant flow relationship with said condensing means and said evaporating means and mounted on said supporting means, and means for circulating air to be dehumidified first in heat exchange relation with the evaporator means and then in heat exchange relation with the condensing means, said refrigerant evaporating means and condensing means comprising a one-piece roll bonded heat exchange element having one set of refrigerant passages formed therein for condensing and another set of refrigerant passages for evaporating refrigerant.

2. In a unitary portable dehumidifying apparatus, a one-piece sheet metal element forming a combination refrigerant evaporating means and a condensing means, a refrigerant compressor having its outlet connected to said condensing means and its inlet connected to said evaporating means, pressure reducing means connected between said condensing means and said evaporating means, and means for circulating air to be dehumidified first in heat exchange relation with the evaporator means and then in heat exchange relation with the condensing means, said sheet metal element comprising a one-piece roll bonded strip having elongated slots disposed between said evaporating means and said condensing means so as to restrict the conduction of heat therebetween.

3. In a dehumidifying apparatus, a refrigerant evaporating means, a refrigerant condensing means, refrigerant compressor means having an outlet connected to said condensing means and having an inlet connected to said evaporating means, a' flow control means connecting the outlet of said refrigerant condensing means to the inlet of said refrigerant evaporating means, said refrigerator evaporatingmeans and said refrigerant condensing means comprising a one-piece sheet metal element having a pair of internally disposed refrigerant passages for evaporating and condensing refrigerant respectively, said element having elongated slots formed therein for thermally separating said evaporating passages from said condenser pas.- sages, and means for flowing air over said evaporating means and thereafter over said condensing means.

4. In a dehumidifying apparatus, a refrigerant evaporating means, a refrigerant condensing means, refrigerant compressor means having an outlet connected to said condensing means and having an inlet connected to said evaporating means, a flow control means connecting the outlet of said refrigerant condensing means to the inlet of said refrigerant evaporating means, said refrigerator evaporating means and said refrigerant condensing means comprising a one-piece roll bonded element having a pair of internally disposed refrigerant passages for evaporating and condensing refrigerant respectively, said element being of reduced cross section between said evaporator passages and said condenser passages so as to reduce the transfer of heat from said evaporator passages to said condenser passages by conduction, said refrigerant passages having irregular wall portions exposed to the air to be dehcmidified, and fan means for circulating air first over said evaporator passages so as to remove moisture therefrom and thereafter over said condenser passages to reheat the air.

5. In a dehumidifying apparatus, a one-piece sheet metal element having a refrigerant evaporating portion and a refrigerant condensing portion arranged in side by side relationship, a refrigerant compressor, refrigerant flow connections between said compressor and said portions, and means for circulating air to be dehumidified first in heat exchange relation with said evaporator portion and then in heat exchange relation with the condensing portion, said sheet metal element comprising a relatively long and narrow strip having slot means between said evaporator and condenser portions, said strip being wrapped about a central axis so as to form a plurality of passages radially spaced from one another about said central axis.

6. In a dehumidifying apparatus, a one-piece sheet metal element having a refrigerant evaporating portion and a refrigerant condensing portion arranged in side by side relationship, a refrigerant compressor, refrigerant flow connections between said compressor and said portions, means for circulating air to be dehumidified first in heat exchange relation with said evaporator portion and then in heat exchange relation with the condensing portion, said sheet metal element comprising a relatively long and narrow strip having slot means between evaporator and condenser portions, said strip being wrapped about a central axis so as to form a plurality of passages radially spaced from one another about said central axis, and a condensate collecting receptacle beneath said sheet metal element, said central axis being disposed horizontally above said receptacle.

7. in a dehumidifying apparatus, a refrigerant evaporating means, a refrigerant condensing means, refrigerant compressor means having an outlet connected to said condensing means and having an inlet connected to said evaporating means, a flow control means connecting the outlet of said refrigerant condensing means to the inlet of said refrigerant evaporating means, said refrigerator evaporating means and said refrigerant condensing means comprising a one-piece sheet metal element having a pair of internally disposed refrigerant passages for evaporating and condensing refrigerant respectively, said element having elongated slots formed therein for thermally separating said evaporating passages from said condenser passages, and means for flowing air over said evaporating means and thereafter over said condensing means, said refrigerant passages having spaced obstructions formed therein for dividing said passages into a plurality of parallel passages at said obstructions, said obstructions comprising indentations in the outer surfaces of said sheet metal element whereby said outer'surfaces of said sheet metal element are provided with undulations over which the air flows.

References Cited in the file of this patent UNITED STATES PATENTS 

